Integrated water resources planning using weap model in the cau river basin

THUY LOI UNIVERSITY INTEGRATED WATER RESOURCES PLANNING USING WEAP MODEL IN THE CAU RIVER BASIN Nguyen Thi Thuy Linh MSc Thesis on Intergrated Water Resources Management February 201

THUY LOI UNIVERSITY

INTEGRATED WATER RESOURCES PLANNING USING

WEAP MODEL IN THE CAU RIVER BASIN

Nguyen Thi Thuy Linh

MSc Thesis on Intergrated Water Resources Management

February 2015

THUY LOI UNIVERSITY

NGUYEN THI THUY LINH

INTEGRATED WATER RESOURCES PLANNING USING

WEAP MODEL IN THE CAU RIVER BASIN

Major: Intergrated Water Resources Management

THESIS OF MASTER DEGREE

Supervisors:

1 Dr Ngo Van Quan

2 A/Prof Pham Quy Nhan

This reseacrch is done for the partial fulfilment of requirement for

Master of Science Degree at Thuy Loi University (This Master Programme is supported by NICHE – VNM 106 Project)

February 2015

ABSTRACT

The Cau River is a tributary of the Thai Binh river system in the North of Vietnam Different water users (agriculture, domestic, industry…) are present in the basin Rising population and increasing water provision in rural and urban areas, in conjunction with the development of the industry or agriculture are going to greatly worsen the complexity of future water resources planning in what is already a water-stressed basin

Being able to assess the ability of the basin to satisfy potential water demands is decisive in order to plan for the future and make positive decisions In this study, a scenario analysis approach was used in conjunction with the Water Evaluation and Planning model, in order to assess the impacts of possible water demands on the water resources of the Cau river basin in 2030 For each scenario, the water resource implications were compared to a 2012 “baseline scenario.” The model enabled analyses of unmet water demands, and water storage for each scenario

The model results show that for the different scenarios considered in this study the implementation of the water resources allocation will increase the shortages for other sectors The construction of the main water storage infrastructure proposed by irrigation planning in the Cau river basin, in conjunction with the application of the percentage allocation method, can reduce the unmet demands and shortfalls to levels lower than, or similar to, those experienced in the 2012 baseline However, in all cases these interferences will be inadequate to completely meet the demands of all the sectors A tight control of the growth in future demands is essential, although this may be difficult in a rapidly developing country like Vietnam

DECLARATION

I hereby certify that the work which is being presented in this thesis entitled,

“Integrated water resources planning using the WEAP model in the Cau river basin”

in partial fulfillment of the requirements for the award of the Mater of Science in Integrated Water Resource Management, is an authentic record of my own work carried out under supervisions of Dr Ngo Van Quan and Associate Professor Dr Pham Quy Nhan

The matter embodied in this thesis has not been submitted by me for the award of any other degree or diploma

Date: February 24, 2014

Nguyen Thi Thuy Linh

ACKNOWLEGEMENT

This study was completed in the Faculty of Water Resources Engineering of Thuy Loi University I am sincerely grateful to all my supervisors, Doctor Ngo Van Quan and Associate Professor Doctor Pham Quy Nhan; teachers who have always encouraged and motivated me and who have given enthusiastic guidance and suggestions during the learning process and completion of my thesis

I am sincerely grateful thanks to the supporters of the project NICHE VNM-106 of the Dutch government (NUFFIC)

I also would like to express my sincere gratitude to the teachers in the Faculty of Water Resources Engineering, who were helpful in conveying knowledge and technical expertise during my study

encouraging and creating favorable conditions in my study and my thesis process Because of the limited time and experience, the thesis has inevitable shortcomings Therefore, I look forward to advice from the teachers so that my thesis will be more complete

STUDENT

NGUYEN THI THUY LINH

TABLE OF CONTENTS

ABSTRACT 1

DECLARATION 2

ACKNOWLEGEMENT 3

LIST OF FIGURES 5

LIST OF TABLES 6

Chapter 1: INTRODUCTION 8

1.1 Background 8

1.2 Problem Statement 9

1.3 Objective of study 10

Chapter 2: LITERATURE REVIEW 11

2.1 Integrated water resources management 11

2.2 Integrated water resources planning 12

2.3 Integrated water resources planing in Vietnam 15

2.4 Some model about water allocation 17

2.4.1 GIBSI model………18

2.4.2 BASIN model……… 18

2.4.3 MIKE model………20

2.4.4 WEAP model……… …20

Chapter 3: MATERIAL AND STUDY AREA 24

3.1 Characteristic of Cau river basin 24

3.2 Water Resources issues 26

3.3 Social-economic development 27

3.4 Current water use for each sector: 30

Chapter 4: METHODOLOGY 32

4.1 Conceptual framework 32

4.2 WEAP method 33

4.2.1 Program Structure: 34

4.2.2 Using WEAP model 37

CHAPTER 5: RESULTS AND DISCUSSIONS 39

5.1 Results of calculation water demand in the current situation 39

5.1.1 Divide to small sub-basins to calculate water demand: 39

5.1.2 Determine water demand in sub-basins 38

5.1.3 Calculate flow rate in sub-basins……….46

5.1.4 Nui Coc reservoir in Cong river sub-basin……… 47

5.2 Results of water allocation in current situation 47

5.3 Water allocation under scenarios to develop society and economy of the Cau river basin 45

5.3.1 Results of water allocation for the 2013-2030 period 49

5.3.2 Results of water allocation for 4 scenarios in the future (from 2013 to 2030) 52 5.3.3 Select option and propose solution for Integrated water ressources planning in the Cau river 61

5.4 Discussions: 64

CHAPTER 6: SUMMARY, CONCLUSIONS AND RECOMMENDATIONS67 6.1 Summary and Conclusions 67

6.2 Recommendations 68

6.3 Future works: 69

REFERENCES 70

APPENDIX 72

LIST OF FIGURES

Figure 2.1: Water resources planning process 14

Figure 3.1: Overview of the Cau river basin and river network (Institute for Water Resources Planning Hanoi, 2009) 24

Figure 4.1: The flow chart of analysis water allocation planning for the Cau River Basin 33

Figure 5.1: Four Sub-basins in Cau river basin 40

Figure 5.2: Modeling diagram about water allocation in current situation 48

Figure 5.3 Results of calculation water shortage in 2012 48

Figure 5.4: Results of water demand in 2030 with orientated development plan 50

Figure 5.5: Results of water demand for the 2013-2030 period with orientated development plan 50

Figure 5.6: Result of calculation water shortage in 2030 (billion m3) 51

Figure 5.7: Develop scenarios and calculate water balance under scenarios 54

Figure 5.8 Results of water demand in 2013 of 4 scenarios 55

Figure 5.9: Results of calculations water shortage for 4 scenarios 56

Figure 5.10 Chart of water shortage of water users in 2030 - scenario 1 (million m3)57 Figure 5.11 Chart of water shortage of water users in 2030 - scenario 2 (million m3)58 Figure 5.12 Chart of water shortage of water users in 2030 - scenario 3 (million m3)59 Figure 5.13 Chart of water shortage of water users in 2030 - scenario 4 (million m3)60 Figure 5.14 Results of calculation water shortage for scenarios 4 and 5 63

LIST OF TABLES

Table 5.1: The data for Four Sub-basins in Cau river basin 41

Table 5.2: The main sectors of water used in the Cau river basin 42

Table 5.3: Irrigation water demand in the sub-basins of Cau River basin 42

Table 5.4: Domestic water demand in the sub-basins of Cau River basin 43

Table 5.5: Industrial water demand in the sub-basins of Cau River basin 44

Table 5.6: Summary of calculating water demand in 2012 of each sub-basin in the Cau river basin 45

Table 5.7: The Meteorological stations in Cau river basin 46

Table 5.8: Average flow in sub-basin (m3/s) 46

Table 5.9: Result of unmet demand in 2012(million m3/s) 49

Table 5.10: Unmet demand of water supply for the 2013-2030 period (million m3)51 Table 5.11: Summary of 4 scenarios of water resources in the Cau river basin 54

Table 5.12: The water demand for 4 scenarios for the 2013-2030 period (billion m3) 55

Table 5.13: Unmet demand of 4 scenarios for the 2013-2030 period(billion m3) 56

Table 5.14 The results of the water shortage of water users in 2030 - scenario 1 (million m3) 57

Table 5.15 The results of the water shortage of water users in 2030 - scenario 2 (million m3) 58

Table 5.16 The results of the water shortage of water users in 2030 - scenario 3 (million m3) 59

Table 5.17 The results of the water shortage of water users in 2030 - scenario 4 (million m3) 60

Table 5.18: The unmet demand for scenarios 4 and 5 for the 2013-2030 period (million m3) 63

Chapter 1: INTRODUCTION

1.1 Background

Water seems to be an endless resource, the inexhaustible gift of nature This was a fact more than 30 years ago, but with the many changes in the lives of people, the economic situation… the shortage of water has become one of the top concerns for humanity Today, water is used in an unsustainable way in the majority in the world In all the countries in the world water is predicted to become scarcer by 2025

or even earlier due to continuously increasing demand This reality constitutes a major threat towards sustainable development and achievement of millennium development goals in the region About only 1% of the world’s fresh water, occurs in the region with 5% of the world’s total population Water demands have dramatically increased as a consequence of a high population growth rate, expansion of agriculture, and the lack of and a weak water policy Many countries actually suffer, think of the Middle East, North Africa, there are areas there too that are severely affected by scarce water resources are now suffering from water deficiency and other countries will face this problem in the near future

Hence, we need to regulate the water usage to ensure a sustainable, equitable and efficient utilization of the resource The allocation of the water resources is normally made through a permit or licensing system, which the system enables the government or state authorities to control the resources taking into account all stakeholder interests In our country with abundant water resources this may not be needed but with the increased pressure on the water resources, both in terms of quantity and quality, the abundant water supply is becoming a rare situation

In recent years, the research applies mathematical models as a tool to support integrated management of water resources, when considering water resource development, water resource planning, administration and management of water resources in river basin in the world as well as in the country increasingly powerful place The tool applies mathematical models to contribute in the integrated management of water resources, water resource managers, and the household sector

water use in the river basin will have, as a result of this tool, a more synthetic and more comprehensive vision of the water resources in the river basin At the same time, stakeholders seek consensus, shared opportunities and orientations to exploit water resources in the basin to meet the immediate and long term goals

The Cau river basin is selected as the subject of the research in which information on water resources, water resources development (basin planning and water allocation), and institution and management mechanisms in the basin

is collected and analyzed to identify challenges and development trends in basin water resources and to propose appropriate solutions to achieve the objectives of the project

1.2 Problem Statement

In the Cau river basin, different water users (rural, urban, subsistence, commercial irrigated agriculture, industry, etc.) are present in the basin where injustice is an issue in the access to water There has been a significant transformation of the water and land legislation in Vietnam This will affect future land distribution and water allocation The development of the industry the construction of new power generation plants, along with the population growth, the revitalization of small-scale irrigation schemes and the improvement in accessibility

to water in the rural areas, all are going to increase the water demands

On the other hand, there are several socio-economic, political and legal processes taking place in the Cau river basin that will affect the water demand and the allocation of water Being able to assess the capacity of this area to satisfy future water demands is essential in order to plan for the future and make wise decisions Moreover, under the impact of climate change, the Cau River basin faces a rising tendency of water shortage The water supply for domestic use, the industry, and livestock is sufficient; however, it is the water shortage in the basin due to irrigation requirement, which is the major problem Water shortage happens in the dry season when the river flow goes down, rainfall is low, and evaporation is high In the rainy season, total rainfall is high, and there is no water shortage This thesis has identified

the use of modeling tools in conjunction with scenario analyze as an important approach to develop water management strategies and to achieve integrated management of water resources

However, due to the limitation of funds, the scope of the research, the expertise and time, the project could only be carried out for a part of the water sector activities in the Cau river basin related to allocation, development, and management

of the basin water resources, particularly water sector investment in the basin A detailed analysis will be part of a new research project

1.3 Objective of study

The main objective of the study is to apply Water Evaluation and Planning System (WEAP) as the tool supporting in allocation planning of water resources in the Cau river basin Specific objectives of the study are:

• To develop a conceptual framework of water allocation for the Cau river basin;

• To use the WEAP model to simulate and develop the scenarios of water resources allocation for the current scenario and the 2013-2030 period in the Cau river basin;

• To analyze, assess and select the scenario for water resources planning in the Cau river basin

Chapter 2: LITERATURE REVIEW

2.1 Integrated water resources management

The integrated water resources management approach helps to manage and develop water resources in a sustainable and balanced way, taking account of social, economic and environmental interests It recognizes the many different and competing interest groups, the sectors that use and abuse water, and the needs of the environment The integrated approach coordinates water resources management across sectors and interest groups, and at different scales, from local to international

It emphasizes involvement in national policy and law making processes, establishing good governance and creating effective institutional and regulatory arrangements as routes to more equitable and sustainable decisions A range of tools, such as social and environmental assessments, economic instruments, and information and monitoring systems, support this process

The use of scientific means to enhance understanding through modeling of the current and possible scenarios due to the various water resources development and changes in supply conditions forms a decision support for water managers at the catchment level Such modeling can be achieved through; water balance models, ground water flow models and economic water use models (Alfarra, 2004)

Water resources planning, once an exercise based primarily on engineering considerations, increasingly occurs as part of a complex, multi-disciplinary investigation that bring together a wide array of individuals and organizations with varied interests, technical expertise, and priorities In this multi-disciplinary setting, successful planning requires effective IWRM models that can clarify the complex issues that can arise IWRM is viewed as a systematic process for the sustainable development, allocation and monitoring of water resources use in the context of social, economic and environmental objective (Cap-Net, 2005)

In any catchment, water availability problems occur when the demand for water exceeds the amount available during a certain period Freshwater shortages occur frequently in areas with low rainfall and high population density and in areas

with intensive agricultural or industrial activity The Cau river basin has large spatial and temporal differences in the amount of fresh water available These are felt more because of rainfall variability in the basin and the differences are expected to change due to climate changes Other pressures on water quantity arise from the main sectorial users of water, such as agriculture, livestock, households, vital ecosystems tourism and industry The impacts of over abstraction of available water include decreases in groundwater levels and surface water flows that in turn can lead to impacts on associated aquatic and terrestrial ecosystems In addition, over abstraction

of groundwater and lack of sufficient recharge can lead to the intrusion of salt water

at the lowland aquifers in the catchment

2.2 Integrated water resources planning

Integrated Water Resources Planning (IWRP) defines a approach to the management of water systems combining water supply, water demand, and water quality IWRP evolved from a growing recognition of the interconnection of environmental systems and society’s impacts within them (Beecher, 1995) In many areas, increasing populations and water demands have exceeded regionally-minded planning; by sharing resources with neighboring areas, planners have found more cost-effective solutions to water scarcity

There are three basic planning paradigms that are used in water resources planning, regardless of the specific steps or approaches applied in the planning process These adigms are the planning iteration, screening, and scoping These techniques are required; water resource planning is a very broad process and setting the boundaries and constraints of a study are often difficult Often budget and time limitations help define the breadth of the study that can be performed, but because water resources planning is such an open-ended process, the three paradigms presented here are very useful in guiding the process Each planning characteristic is discussed below:

(1) Planning iteration: Iteration implies doing the same thing more than once

In planning, iteration implies returning to an analysis when more information is

available, when a different level of detail is necessary, or when new evaluation techniques have emerged

The planning process is one that is improved when it is performed more than once This not only implies that reviews improve evaluations, but that the level of detail of evaluations is likely to change during the planning process Planning is not a simple linear process Any process that encourages feedback from stakeholders will naturally require some degree of iteration Feedback typically creates new information or helps to identify new priorities or areas of increased interest Incorporating this information improves the quality of a plan if it is considered

(2) Screening: Screening is a basic systems engineering concept Screening is the process of iteratively examining alternatives to select those which will receive further consideration and those that will not A principal goal of screening is to effectively reduce the quantity of detailed analysis that is necessary, without eliminating alternatives which should be evaluated fully Screening does not imply full evaluation and ranking, it implies making use of expertise and sound judgment to use one’s time effectively Without some form of screening, almost any water resource planning effort would become too complex and intricate to accomplish With screening, promising alternatives are provided an opportunity for full evaluation and inferior alternatives are excluded from further evaluation

(3) Scoping is also another basic systems engineering concept Scoping identifies the boundaries of the problem to be addressed and the boundaries of the solutions to be considered Scoping is particularly important in evaluating water resources planning because the National Environmental Policy Act defines scoping

as a required process In that act, scoping is defined as “an early and open process for determining the scope of issues to be addressed and for identifying the significant issues related to a proposed action” Scoping has been used in many studies as a formal procedure to ensure the input of stakeholders in the planning process Although there are many ways to organize the planning process, a number of specific procedures with well identified steps have been suggested in the literature (Palmer,

1999; Keyes and Palmer, 1995) The seven step process described here is an example

of a “disciplined, iterative process.”

Figure 2.1: Water resources planning process

This implies that all steps must be performed and recognizes the natural feedback that exists between all steps The number of steps and their boundaries are less important than the general planning philosophy, that is, good water resources planning involves carefully defining the challenges faced, defining the planning environment and including all those that might impact or be impacted by the plan, creating a comprehensive and creative set of alternatives for addressing the challenges, selecting among those alternatives the one plan that best addresses the objectives and constraints of the challenge, and creating an comprehensive approach

to implementing that plan

2.3 Integrated water resources planing in Vietnam

In our country, there have been some studies on water resources planning on the basis of economic efficiency of water use, such as the studies about water resources planing in Dong Nai river basin or in the Red river basin

The basis and principles for water resources planning are applying in Vietnam:

In terms of the system of legal documents including current laws, decrees, circulars, the existing two legal documents specified on water resources planning, such as:

- Law on water resources (17/2012/QH13)

- Decree 120/2008/ND-CP on river basin management

- Decree 201/2013/ND-CP: regulations detailing the implementation of some articles of Law on Water Resources

These documents shall be as follows:

- A river basin planning comprises the following component plannings:

a Planning on allocation of water resources;

b Planning on protection of water resources;

c Planning on prevention, combat and address of consequences of harms caused

by water

- A component planning may cover the whole basin, one or a several sub-basin

In this thesis, I will focus on one component planning: planning on the allocation

of water resources According to the Article 14 (Decree 120/2008/ND-CP), the major contents of a planning on allocation of river basin water resources are:

- Assessing the volume and quality and forecasting the development trends of water resources, and the current status of water resource exploitation and use for every water source

- Identifying water needs and existing problems in the comprehensive exploitation and use of water resources and establishing the priority order and capacity to meet water needs for daily life, agriculture, hydro-power, fishery, industries, transport, tourism, other socio-economic activities and environmental protection for every water source

- Determine the priority order and water resource allocation rates in the water resource exploitation and use for daily life and other purposes, including water needs for environmental protection in case of droughts or water shortage

- Determining water use purposes, minimum flows to be maintained in river sections in basins and necessary measures to deal with matters specified in Clause 2 of this Article

- Proposing networks for water resource supervision, water use oversight and the adjustment of parameters or adjustment of the current operation of water resource-exploiting and -using works (if necessary)

- Identifying needs for water transfer among sub-basins within a river basin; needs for water transfer with other river basins (if any)

- Proposing construction measures for water resource development with a view to meeting the needs for water for socio-economic development in the basins

- Identifying implementation solutions and schedule for planning

Besides the content of article 14 from 120/2008/ND-CP, the thesis will concern about priority in the water supply These documents shall be as follows: The highest priority for water supply is domestic water demand in all other purposes (Article 54 Law on Water Resources) and provide competent priority water supply during drought (Article 5, 45, 46 Decree 201/2013/ND-CP), but not clear guidance

on the relationship between the priorities or purpose is selected, if any, take precedence over the other uses As follows:

The regulation and distribution of water resources for different use purposes must be based on the water resource master plan, the actual capacity of water sources and water resource regulation and distribution plans, and adhere to the following principles:

- Assuring fairness and rationality among water users on the same river basin, between upstream and downstream areas and between the right bank and the left bank;

- Prioritizing water in terms of both quantity and quality for use for daily-life activities and agricultural production to assure food security and meet other essential needs of people;

- Assuring the maintenance of the minimum flow and groundwater exploitation limits;

- Combining the exploitation and use of surface water with exploitation and use

of groundwater and rainwater; increasing storage of water in the rainy season for use in the dry season

Therefore, the decree and law provide the basis for the formulation and implementation of water resources planning Laws and decrees also identified a number of fundamental issues, as required to determine the priority of water supply

to cope with water shortages, but in reality does not fully solve the problem And it can be said that in the current situation, consider the allocation problem of water resources in the basin in our country concerned only 5 years ago and in the initial stage of research methodology

The main principles and objectives outlined in the Law on Water Resources and the related regulations on water resources planning can be interpreted as follows:

Principle 1: The need for sustainable water use and no degradation of water resources;

Principle 2: Water activities are first priority;

Principle 3: utilization of water shall not exceed the "real volume" of water, and Principle 4: planning and allocation of water resources to ensure “equity”

2.4 Some model about water allocation

Due to the requirements of developing river basin water resources to meet the requirements of economic development - social Today the world has done to build the model, the model system to evaluate the impact of human conditions to buffer surface water resources Maybe at some models are widely used around the world as follows:

2.4.1 GIBSI model

GIBSI system model is applied to the watershed ecosystems in Canada and the development of industry, agriculture, urban complex GIBSI is an integrated modeling system running on a PC to the test results the impact of agriculture, industry, water management both in terms of quantity and quality of water resources

GIBSI model for forecasting the impact of the industry, forest, urban, agricultural projects for the natural environment, effective water users warned in advance and respect standards the quantity and quality of water resources

GIBSI is a set of model components include:

- HYDROTEL hydrological model;

- Model physical resolution remote sensing systems, geographic information systems

- USLE model for sediment transport and erosion;

- Model spreading chemicals in agriculture is based on the modeling of nitrogen, phosphorus, pesticides (using a module in SWAT model);

- Models QUAL2E water quality, water quality model to simulate the elements: the diffusion and flocculation of water-soluble substances (pollutants); the development of algae; the cycle of nitrogen, phosphorus; the decay Coliform; how ventilation; the temperature of the water

2.4.2 BASIN model

Model basins built by the Office of Environmental Protection(The United States) The model is constructed to provide a better assessment tools and more integrated emission sources and not concentrate concentrated in the management of water quality in the basin This is a model of environmental systems analysis and multi-purpose, capable of application to a country, a region to carry out research on water quality and quantity, including the basin The model was designed to meet three objectives: (1) Convenience in the control of environmental information; (2) Assist in the analysis of environmental systems; (3) Provide a system of basin management plans

Model basins are a useful tool in research on water quality and quantity With the many modular components in the system, computation time is shortened, many problems are solved and the information management more efficient models With the use of GIS, model basins more convenient to denote the combination of information and (land use, traffic emissions sources, water regression, ) in any one location The components of the model allows users to determine the impact of emissions from the point of focus and unfocused Combination of modular components can help to analyze and manage the basin towards:

- Identify and prioritize the limits of the environment;

- Characteristics of emission sources and determine the magnitude and potential emissions

- Sets the amount of emissions from point sources and not concentrate and focus on the transport process as well as in the river basin

- Identify, compare the relative value of the pollution control strategies

- Demonstration and announced to the public in the form of tables, figures and maps

BASIN model includes the following components model:

- Model of the river: QUAL2E, version 3.2 model water quality

- The model basin: WinHSPF is a watershed model used to determine the concentration of the waste from the waste sources and not concentrated focus in the river; SWAT is a model based on physics is built to predict the impact of land use activities in the basin to the flow regime, determine the amount of sediment and chemicals used in agriculture throughout the basin

- The propagation model: PLOAD, is a model of viral contaminants, PLOAD identify sources of emissions, the average concentration in a certain time period

The function of the model allows users BASIN demonstrated, data and perform analysis according to the different goals BASIN model is widely used in the

United States, it is convenient for storage and analysis of environmental information,

and can be used as a tool to support decision making in the process of building

management framework basin

2.4.3 MIKE model

Danish Hydraulic Institute (DHI) to build software evaluation and analysis of the

problems of water quality and quantity, the software is helpful in planning the

development and management of water resources sustainability perspective MIKE

BASIN software with ArcView GIS interface is a model simulating water basin

MIKE model includes a lot of software you have the functions and tasks such as

MIKE 11, MIKE 21, MIKE 31, MIKE GIS, MIKE BASIN, MIKE SHE, MIKE….It is

possible applications to calculate the distribution of water in the basin both in quantity and

quality and has been applied to calculate the allocation of water resources to bring more

efficiency to the basin in the world

2.4.4 WEAP model

The WEAP model was developed by the SEI to enable evaluation of planning and

management issues associated with water resources development The WEAP model can

be applied to both municipal and agricultural systems and can address a wide range of

issues, including sectoral demand analyses, water conservation, water rights and allocation

priorities, stream flow simulation, reservoir operation, ecosystem requirements and project

cost-benefit analyses (SEI 2001)

The WEAP model has three primary functions (Sieber et al 2004):

• Simulation of natural hydrological processes (e.g., evapotranspiration, runoff

and infiltration) to enable assessment of the availability of water within

a catchment

• Simulation of anthropogenic activities superimposed on the natural system to

influence water resources and their allocation (i.e., consumptive and

non-consumptive water demands) to enable evaluation of the impact of human water use

• Simulation of water allocation, the elements that comprise the water supply system and their spatial relationship are characterized for the catchment under consideration The system is represented in terms of its various water sources (e.g., surface water, groundwater, desalinization, and water reuse elements); withdrawal, transmission, reservoirs, and wastewater treatment facilities, and water demands (i.e., user-defined sectors but typically comprising industry, mines, irrigation, domestic supply, etc.) The data structure and level of detail can be customized (e.g., by combining demand sites) to correspond to the requirements of a particular analysis and constraints imposed by limited data A graphical interface facilitates visualization of the physical features of the system and their layout within the catchment

demand-The WEAP model essentially performs a mass balance of flow sequentially down a river system, making allowance for abstractions and inflows To simulate the system, the river is divided into reaches The reach boundaries are determined by points in the river where there is a change in flow as a consequence of the confluence with a tributary, or an abstraction or return flow, or where there is a dam or a flow gauging structure Typically, the WEAP model is applied by configuring the system

to simulate a recent “baseline” year, for which the water availability and demands can be confidently determined The model is then used to simulate alternative scenarios (i.e., plausible futures based on “what if” propositions) to assess the impact

of different development and management options The model optimizes water use in the catchment using an iterative Linear Programming algorithm, whose objective is

to maximize the water delivered to demanding sites, according to a set of defined priorities All demand sites are assigned a priority between 1 and 99, where 1

user-is the highest priority and 99 the lowest When water user-is limited, the algorithm user-is formulated to progressively restrict water allocation to those demand sites given the lowest priority In the world and in our countries, many countries widely used WEAP model to allocate water resources

Up to the present time, relating to the application model WEAP in countries around the world with more than 30 projects in the country evaluated countries on most continents, including the US, China, Thailand, India, Mexico, Brazil, Germany, South Korea, Ghana, Kenya, South Africa, Egypt, Israel and Oman

In the Jordan valley, the authors said that water was scarce, yet key to its economic development A fast growing population and expanding agricultural sector

to create demands for new water resources They present a Water Evaluation and Planning (WEAP) model of the Jordan Valley (JV) to evaluate alternative water supply options WEAP accommodates the extensive primary and secondary spatial data sets behind our empirical analysis and allows the simulation of various water supplies and demand scenarios This paper reports on the implementation and calibration of the WEAP model against dam operating rules, showing that it is possible to reproduce historical dam volumes accurately enough by analysis The paper also describes five alternative water supply scenarios for the JV: business as usual, increasing treated wastewater in irrigation, climate change, and two combined scenarios climate change with increasing reuse, and altered patterns of agriculture to calculate the impact on the demand and supply gap by the year 2050

WEAP Models are being widely used in order to assess the impacts of future development trends, water management strategies, climate change, etc on the availability of water resources For instance, WEAP Model has been developed in order to assess the impacts of different water management decisions on the availability of water in the different watersheds of Texas (Wurbs, 2005)

The Water Evaluation and Planning System Version (WEAP) is an IWRM model that seamlessly integrates water supplies generated through watershed-scale hydrologic processes with a water management model driven by water demands and environmental requirements WEAP considers demand priorities and supply preferences, which are used in a linear programming heuristic to solve the water allocation problem as an alternative to multi-criteria weighting or rule based logic approaches It introduces a transparent set of model objects and procedures that can

be used to analyze a full range of issues faced by water planners through a scenario based approach These issues include climate variability and change, watershed condition, anticipated demands, ecosystem needs, the regulatory environment, operational objectives, and available infrastructure WEAP was developed by the Stockholm Environment Institute's Boston Centre at the Tellus Institute The model is designed to assist rather than substitute the skilled planner Arranz and McCartney (2007) have also applied the model to the Olifants catchment in South Africa In their analysis, the model performed well in doing quick analysis of current and future water demands

Chapter 3: MATERIAL AND STUDY AREA

3.1 Characteristic of Cau river basin

The Cau River is a level 1 tributary of the Thai Binh river system in coordinates from 21007' to 22018' N and 105028' to 106008' east longitude, with a total catchment area of 6030 km2 in which the forestry and agriculture area are accounts of 64.206 ha and 241,834 ha respectively The total length of the Cau River

is about 2,885km The Cau River has 27 tributaries of more than 10km in length; the largest tributary of the river is a Kong river with area of 950 km2 following by Ca Lo River of about 891km 2

Figure 3.1: Overview of the Cau river basin and river network (Institute for

Water Resources Planning Hanoi, 2009)

The Cau river basin covers the area of six provinces, namely Bac Kan (4 districts), Thai Nguyen (whole province), Bac Giang (5 districts), Bac Ninh (5 districts), Vinh Phuc (7 districts) and Hanoi city (4 districts)

The basin geology is complicated and diversified and classified into three main regions: mountainous, hilly and delta areas The basin land is suitable for agriculture: fruit tree and industrial crop in mountainous and hilly areas; paddy and subsidiary crop in delta areas

Temperature: The basin mean annual temperature arranges from 18-240C, where the lowest annual temperature is Tam Dao area (180C) and the highest is Hanoi city (23,90C)

Rainfall: The basin mean annual rainfall ranges from 1533mm (Bac Kan province) to 2495mm (Tam Đảo) but uneven distributes in the rainy and dry seasons; the rainy season starts from V to IX with an amount of 80-85% of annual rainfall, dry season starts from X to IV next year with an amount of 15-20% of annual rainfall

Evaporation: The mean evaporation of year ranges from 800-400mm, with the highest value is in Bac Giang province 1000mm/year and the lowest is 541mm/year

at Tam Dao

Hydrology: The mean of the flow module in the western part of the Cau basin, where the Tam Dao mountain range with elevation more than 1,500m compare with sea level, with high coverage of forest, is about 30 l/s.km2, and the upstream of the Cau basin, where the annual rainfall is about 1700 mm, is about 21.4 l/s/km2

• The variation of the river flow is not so high between years with the value of flow coefficient ranges from 0.25-0.4

• The mean annual runoff of the basin is about 4.9 billion cubic meters and uneven distributed over space and time

The groundwater in Dai Tu district is poor with capacity of less than 100m3/day with high concentrations of minerals The groundwater of the Thai Nguyen city has been fully investigated and this showed that the total capacity of groundwater of about 50,774 m3/day, which is enough to meet the demand for Thai

Nguyen and its surrounding area The period and time for exploitation of this source depends on the provincial exploitation plan Groundwater of the Song Cong town is not abundant; the groundwater capacity of the geographical compiles Jura-Keta is only about 150-200m3/day so the surface water of the Cong river is the main water supply sources for domestic and productive uses The groundwater reserve at (A+B) level of Pho Yen District is about 11,286m3/day that meets the demand of water supply for Ba Lang town and surrounding areas The average groundwater exploitation for domestic use in Dong Anh and Dap Cau areas is about 4,000-5,000 m3/day

3.2 Water Resources issues

The average annual amount of water per capital of the river is less than national average (1,086m3/ head/year) The uneven distribution of the basin water resources is the main challenge for water supply and for economic development

According to an initial investigation on groundwater, the groundwater resources

of the basin are not abundant and unevenly distributed It is therefore necessary to consider and harmonize the exploitation between surface and groundwater in each region

Although surface and groundwater of the Cau River Basin are not abundant, the basin is adjacent to some large river systems such as Pho Day in the Northwest, the Red River in the west, and Duong River in the south and Thuong River in the Northeast Water from these rivers could be provided for the Cau River basin to serve for water use purposes, especially for downstream area

Due to human activity and climate change, the Cau river basin water resources are deteriorating, the minimum river flow observed at the Thac Rieng station in March/2004 was only 4,9 m3/s while the average monthly river flow in this month is 14.3 m3/s, it means that dry flow has been seriously degraded (The Centre for National Hydrometeology-MONRE)

The water quality in the downstream part of the Cau river basin is heavily polluted by wastewater discharged from residential areas, industrial zones and agriculture It is the most burdensome issue for management

Recently, the number of flash floods occurring in the basin has been increasing The flash flood in Nhan Mon communes of Bac Kan province on 04/07/2009 had killed 13 people and an injured others Houses and other infrastructure were damaged

or destroyed (14 houses destroyed, 215 flooded, 155 forced to resettle) Agriculture was also affected: flooded paddy field: 3 ha, the new plating plant: 3.160 kg; new transplanted paddy: 1 ha; buried paddy area: 30 hectares, pigs, cattle death: 50; irrigation: broken canal: 1.700 m; broken siphon: 16; failure dams/weirs: 16; broken water supply: 2 (Report 132/BC/UBND dated August 14/ 2009 of Bac Can People Committee on loses of flash flood in Pac Nam district from 4/7 to 13/7/2009) The damage in monetary terms is estimated to be VND 113.3 billion

3.3 Social-economic development

3.3.1 Population:

According to population investigation in the basin in 2008, the population of the basin is about 4,512,363 people combining of more than nine ethnicities Average population density is approximately 966 people per km2 Cho Don and Bach Thong districts of Bac Kan province have the lowest population density, from 56-60 people per

km2, the highest population density is Bac Giang province with about 3353 people per

km2, followed by Tu Son town (Bac Ninh province) 2138 people/km2, Gia Lam (Ha Noi) 2001people/km2 (Statistic data of provinces in 2008)

Most of the basin are living in rural areas and account for 87% of the basin population An amazing point is that 92% population who are living in the basin area

of Hanoi capital are living in 32 rural areas in which the ratio in the Soc Son district

is 98% (because the district has not had much investment, primarily people living on agriculture) The ratio between male and female are 49.1% and 51.9% respectively

Currently, the basin population growth rate is about 1.25% /year, and the highest rate is in Bac Ninh province of 1.41%/year (This rate is declining due to the birth planning policy of the government, for example, in Bac Ninh province, in the five-year plan for economic development of the province has set a target that by 2015 would reduce birth rates down also 0.95% and 0.90% in 2020)

3.3.2 Economic:

According to statistic data in 2008, the contribution from different economic sectors in the basin economy is:

• Agro-forestry: 21.2% (agriculture + fishery + forestry)

• Industry and Construction: 46.9%

• Services: 31%

However, depending on geological location and development level, the role of sectors in each province is also different For mountainous provinces such as Bac Kan and Bac Giang provinces, agriculture, aquaculture and forestry are the main sectors while industry is the main sector in delta provinces such as Bac Ninh 56.238%, Vinh Phuc 58.34% Thai Nguyen has developed heavy industry for a long time with two well-known industrial zones, Thai Nguyen and Song Cong, so the contribution of industry in provincial total production is about 62.23% In the capital, Hanoi, the service sector takes the leading role with contribution of 51.2% in the year 2008 The difference in sector contributions causes the difference of average GDP per capita amongst provinces; the highest value is Hanoi capital of about 1,200 USD while the value in Bac Kan and Bac Giang provinces is lower that the national average of about 400-500 USD

Poverty rates have been measured by monthly average income per capita, according to the latest standard of the Government for the period 2006-2010 with different standards as follows: 260,000 dongs for urban, 200,000 dongs for rural (excluding the effect of price index)

According to this standard, poverty rates in Cau river basin increase from the plains to mountainous areas and decrease with time In 2007, the poverty rate was highest in Bac Can: 34.4%, following by Bac Giang: 21.28%; Thai Nguyen: 17.7%, Vinh Phuc: 12%; Bac Ninh: 9.33% and Hanoi: 2.9% Over time, the poverty rate decreased very rapidly, especially in the mountainous provinces In Bac Kan, in 2006 the poverty rate is 41.7%, while the rate in 2008 was only 30.18% Similarly, in Thai

Nguyen province the rate was respectively: 23.74% and 17 74%; Bac Giang: 25.04% and 17.78%

Like other provinces in the basin and in Vietnam, social welfare issues are always given priority attention by the state, especially the mountainous areas where there are large ethnic minority groups

8774 ha of paddy is still rain-fed areas Especially in the upstream area (upper Thac Huong weir) where works irrigate only 36% of arable land, while in the middle and Lower River, irrigation supplies for 80-90% of arable land Water use competition usually occurs in North Duong, the Ca Lo River, where industrial areas, villages and residential areas have been developed These areas have high water requirements which were not taken into account during project design

The total area of maize is as follows:

- In 2008: 38,079 ha, productivity reached 3.4 tons/ha

- In 2008: 56,184 ha, productivity reached 4.06 tons/ha

Total cassava production area:

- In 2005: 6,077 ha, productivity reached 9.0 tons/ha

- In 2008: 5,734 ha, productivity reached 8.44 tons/ha

Livestock: main livestock are cattle, pigs and poultry, production is mostly at the household scale, with industrial livestock concentrated in the delta provinces

According to statistics of the provinces the total number of poultry and cattle have increased over the years

b Industry

Industry in the basin is mainly concentrated in the hilly and delta provinces Before 1990, the industry was mainly mining and mechanical processing Plants are mostly single, small-scale production facilities There are a few industrial parks in industrial-scale areas such as Thai Nguyen industrial zone, Song Cong industrial zone, Vinh Yen, Vinh Phuc, Bac Ninh, Dong Anh

Industrial development achieves higher growth rates primarily due to the effective operation of the processing industry sector with foreign investment (FDI) These sectors are mainly car assembling factory such as Toyota and Honda Currently, investment in industry is focused on areas such as as Noi Bai Industrial Zone-Soc Son, Thang Long industrial zone, Vinh Yen, Vinh Phuc, Yen Phong Industrial Zones

c Tourism

In the area, there are many small tourist areas, each year welcoming tens of thousands of international and domestic visitors The attractive destinations include: Tam Dao Resort, Nui Coc Lake, Dai Lai Resort, etc However, the number of tourists

is limited because of poor infrastructure and lack of tourist advertising

d Urbanization

As result of economic development and re-allocation of basin territory (a result of provincial separation between Bac Giang and Bac Ninh, Thai Nguyen and Bac Kan, Vinh Phuc and Phu Tho), there are now urban areas under the management

of basin provinces, such as Thai Nguyen city, Song Cong town, Vinh Yen town, Bac Giang city, Bac Ninh City, Bac Can town However, these urban areas are not large with low infrastructure levels, incomplete and poorly functioning water supply systems As a result the drainage and wastewater treatment systems do not meet the requirements

3.4 Current water use for each sector:

+ Water for agriculture: Irrigation water demand for crops is calculated with probability of 75%

+ Water for livestock:

For cattle: 2008: 30 liter/day/head, for 2010: 50 liter/day/head

+ Water for industry:

For industrial zones to be constructed: 50-80 m3/ha/day

For the existing industrial zones, water demand is calculated on basis of product value: heavy industry: 200 m3/US$1,000; light industry: 400m3/US$1000 and food industry: 1,000m3/US$1000

+ Water for urban and rural area: Water demand for domestic uses is calculated based on population to be supplied with water:

• 2010:

Rural area: 60 l/p/d Urban area at grade1: 100 l/p/d

• 2012:

Rural area: 80 l/p/d Urban area at grade I: 120 l/p/d

As assessed by the Institute of Water Resources planning, the annual water use (Water provided to fulfill each sector requirements) of all sectors within the basin in

2005 is about 2.076 billion m3, of which the largest water use sector is agriculture, of about 1.54 billion m3, which accounts for about 74 % of total water use of the whole basin Water for industry is 0.173 billion m3;domestic use: 0.163 billion m3 Water is supplied from the hydraulic works, rivers, streams and groundwater

Future water requirements are predicted to grow: by 2010 the amount of water required is 2.207 billion m3, by 2020 increased to 2.553 billion m3 Water use

in agriculture is predicted to be increased, so it will still be the largest water user, accounting for 67% in 2010 and 76% in 2020 of the total water requirements of all sectors Water for industry and domestic uses were similar for both two periods:

accounting for 8.9% and 12.2% 2010; and 9.1% and 12.8% in 2020 respectively

Chapter 4: METHODOLOGY

Using the analysis data about population, development orientation of the river basin is known the tendency of water supply and water used in the Cau River Basin How water supply and use has been impacted by anthropogenic factors Moreover, It

is important to evaluate the trend of agricultural, industrial and domestic water requirements in the river basin Therefore, we find the orientation planning of water resources in the Cau river basin The contents and the rules, was set out in the law on water resources and the decree of river basin management, will be concerned and consider to set-up process and choose the scenario for integrated water resources planning, especially focusing on the allocation of water resources in the Cau river basin

4.1 Conceptual framework

Use of modeling tools in conjunction with scenario analysis as an important approach to developing water management strategies and achieve integrated management of water resources Control of the growth in future water demands is essential, although this may be difficult in a developing country like Vietnam There is a general consensus about integrated water resources planning at catchment level as the approach to use for sustainable water resources management (GWP-TEC, 2009)

With goals have been identified include: (1) build the WEAP modeling to calculate the water balance in the Cau river basin for current status in 2012 and the period from 2013 to 20230; (2) the proposed methodology to plan water resources applied to the Cau river basin On this basis, this study establishes the methodology

to solve planned problem, as the figure 4.1 below:

Figure 4.1: The flow chart of analysis water allocation planning for the Cau

River Basin 4.2 WEAP method

WEAP applications generally include several steps The study definition sets

up the time frame, spatial boundary, system components and configuration of the problem The Current Accounts, which can be viewed as a calibration step in the development of an application, provide a snapshot of actual water demand, pollution

DATA COLLECTION

Water demand

for Agriculture Water demand for Industry Water demand for Domestic

WEAP MODEL

Current

CONCLUSION

Select the allocated scenario

loads, resources and supplies for the system Key assumptions may be built into the Current Accounts to represent policies, costs and factors that affect demand, pollution, supply and hydrology Scenarios build on the Current Accounts and allow one to explore the impact of alternative assumptions or policies on future water availability and use Finally, the scenarios are evaluated with regard to water sufficiency, costs and benefits, compatibility with environmental targets, and sensitivity to uncertainty in key variables

(4) Scenario Explore:

You can highlight key data and results in your system for quick viewing

(5) Note:

Note screen provides a space for users to put all the annotations, commentary on the process of building and calculations with WEAP model

4.2.2 Using WEAP model

(1) Require input data:

For any problem, the requirement input data will be different:

The simulation element:

- Simulate river and tributary;

- Simulate water demand for each sector;

- Require about environmental flow;

- Simulate reservoir and others

The simulation element will be connecting through Transmission Link and Return Flow

(2) Simulate study area:

- Create area;

- Chose years and time steps;

- Put units for parameters;

- Do all steps above and then design river network and input data

(3) Input data for WEAP model:

- For all tributaries, we will input average flow data (Supply and Resources → River);

- For water demand: